Beijing -LRB- CNN -RRB- -- The death toll may climb after a series of earthquakes in southwestern China killed at least 80 people and injured 731 , a state-run news agency reported Saturday .

More than 6,600 homes were destroyed and about 430,000 damaged in Friday 's quakes , Xinhua said .

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Premier Wen Jiabao inspected stricken areas early Saturday and visited the injured , the news agency reported . Wen will direct rescue operations .

President Hu Jintao called for immediate relief efforts , according to China Central Television .

Xinhua reported that 100,000 people have been evacuated and another 100,000 are in need of relocation .

Initial estimates put the `` direct economic losses '' from the tremors at more than half a billion dollars , the news agency said .

Xinhua described the mountainous area hit hard by the quakes as poverty-stricken . It said telecommunications and traffic infrastructure were seriously damaged .

Four earthquakes struck near the border of the provinces of Yunnan and Guizhou between 11:19 a.m. and 1:12 p.m. local time , the U.S. Geological Survey said . Their magnitudes ranged between 4.8 and 5.6 , according to the U.S. agency .

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The first quake took place near the border between Yiliang County in Yunnan and Weining County in Guizhou , Xinhua said .

All four quakes struck at a depth of about 10 kilometers -LRB- six miles -RRB- , the USGS said .

The southwestern region of China is prone to earthquakes . In May 2008 , a magnitude 7.9 quake in Sichuan province caused widespread devastation , killing at least 69,000 people .

CNN 's Steven Jiang contributed to this report .

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Chinese Premier Wen Jiabao visits stricken areas

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The quakes hit near the border of Yunnan and Guizhou provinces in southwest China

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Their magnitudes range between 4.8 and 5.6 , the U.S. Geological Survey says

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More than 430,000 houses are damaged and 6,600 destroyed , state media reports